Engine runs fine although perhaps just a tad to lean/hot rather then rich.
I can run WOT over and over with perfect smoke.
It has great launch and and sounds OK.
As long as I keep it running (for several tanks) the engine will run fine.
If I refuel I can keep the throttle on a little bit and everything is fine.
But if I let it idle for only a few seconds it will rev down and die.
After that the glow plug is done and will not even glow with it out of the engine and into the glow igniter.
This happens OVER and OVER again with brand new plugs.
I run recommended plugs on 20% and the engine is under 1 gallon so far.
I have taken it apart and checked bearings and cleaned carb and everything else.

Engine runs fine although perhaps just a tad to lean/hot rather then rich.
I can run WOT over and over with perfect smoke.
It has great launch and and sounds OK.
As long as I keep it running (for several tanks) the engine will run fine.
If I refuel I can keep the throttle on a little bit and everything is fine.
But if I let it idle for only a few seconds it will rev down and die.
After that the glow plug is done and will not even glow with it out of the engine and into the glow igniter.
This happens OVER and OVER again with brand new plugs.
I run recommended plugs on 20% and the engine is under 1 gallon so far.
I have taken it apart and checked bearings and cleaned carb and everything else.

What could this be?

The element is breaking while you are running, probably because it's lean and hot. It will keep running if though broke but of course, can't be re-fired.

What engine and what plug? A lot of plugs have gone to a cheaper element to keep costs down but they just don't last anymore.

Is the plug discolored at the tip when u take it out of the engine? If it is in one day of running ur to lean which will also gurantee ur engine not lasting much longer running hot, If ur only a gallon in the engine you shouldnt be running it a tad hot it should still be rich because most engines dont even break in till after a gallon. Also if you didnt do a proper break in the engine will always have issues, ive seen a novarossi last 3 days because the guy just threw it in the truggy and opened it up like it was broke in.

i can almost garentee ur rod bushings r shot, i have the EXACT symtoms 2 times n both times my rod bushing were the issue. the first time the upper bushing in the piston totally went, 2nd time the lower bushing had gone outta rounds. i keptpopping plugs n i was pissed!

Is the plug discolored at the tip when u take it out of the engine? If it is in one day of running ur to lean which will also gurantee ur engine not lasting much longer running hot, If ur only a gallon in the engine you shouldnt be running it a tad hot it should still be rich because most engines dont even break in till after a gallon. Also if you didnt do a proper break in the engine will always have issues, ive seen a novarossi last 3 days because the guy just threw it in the truggy and opened it up like it was broke in.

Yes it is a bit brownish rather then ash grey

It is not a day of running, it's ANY AMOUNT of driving until you let it idle for more then 15-20 seconds or so. THEN the plug dies. Pop in a new one and repeat. You can drive one hour straight with no issues but as soon as you let it idle for a longer period of time that plug also dies, repeat again.

This one is broken in and "dropped the balls" already. I said lean rather then rich just to let you know i was NOT running too rich and therefor burning plugs.

I did OF COURSE do a proper break in (heat cycle).

Quote:

Originally Posted by Matt Piva

i can almost garentee ur rod bushings r shot, i have the EXACT symtoms 2 times n both times my rod bushing were the issue. the first time the upper bushing in the piston totally went, 2nd time the lower bushing had gone outta rounds. i keptpopping plugs n i was pissed!

Is that even possible after less then a gallon?
I will take it apart again and look at the bushings.
What is it with a bad bushing that eats plugs? Whats the thinking behind it?

It is not a day of running, it's ANY AMOUNT of driving until you let it idle for more then 15-20 seconds or so. THEN the plug dies. Pop in a new one and repeat. You can drive one hour straight with no issues but as soon as you let it idle for a longer period of time that plug also dies, repeat again.

This one is broken in and "dropped the balls" already. I said lean rather then rich just to let you know i was NOT running too rich and therefor burning plugs.

I did OF COURSE do a proper break in (heat cycle).

i just replace my plug from, the one gallon i ran raced it but it was rich on the low end and running about 235 degress. and it actally gave up before my second gallon really because, it would just would keep on loading up and not idleing right . even if i tried to lean the low end to stop it from doing that and, i even messed with the high end needle a bit.

but with the new plug, the low end runs, better and a constant idle with no drop off and a new fresh prefilter filter and inner filter, and there was a light blue smoke when i hit the gas.

i got my broken in my edmods, and like a dummy dint ask how many tanks he ran though it . but its still tight enough were i cant turn the piston over by hand.

and the old plug, was brown on the suface and the coils i dint check but i am going to.

Is that even possible after less then a gallon?
I will take it apart again and look at the bushings.
What is it with a bad bushing that eats plugs? Whats the thinking behind it?[/QUOTE]

I've only seen the rod bushing thing happen once, but it would blow the plug immediately, and obliterate it at that.

It sounds kinda like the engine is a little hot. If the engine runs too lean, a lot of times it can still stay running, but the plug filiment will have enough of a crack or break to keep it from refiring.